台阶式溢洪道流速水头沿程变化研究  

Research on the Velocity Head of Stepped Spillways

作　　者：于进伟[1] 刘韩生[1] 

机构地区：[1]西北农林科技大学水利与建筑工程学院,陕西杨凌712100

出　　处：《中国农村水利水电》2017年第8期177-179,174,共4页China Rural Water and Hydropower

摘　　要：水流的流速水头是重要的水力参数,可一定程度上反映水流的能量。为研究台阶溢洪道过流断面流速水头的沿程变化规律,将其与同体型的光滑溢洪道流速水头进行对比,引入相对流速水头的概念。通过对26.6°、33.7°、38.7°、48.0°四组坡度,0.5、1.0、2.0 m三种台阶高度的台阶式溢洪道,在单宽流量17.25~62.18 m2/s之间进行模型试验研究。结果表明台阶的流速水头沿程呈现曲线规律,关系复杂不便应用;而非均匀流段上相对流速水头与流程长度呈现良好的线性递增关系,相关系数R2为0.994 8~0.998 8。台阶部分对水流的阻碍效果随单宽流量的减小增大,而与台阶高度、坡度呈递增关系,其中坡度的影响最显著。试验证实了引入相对流速水头的必要性,为台阶溢洪道水力特性的研究提供了依据。The velocity head is an important hydraulic parameter,which can reflect the energy of flow to a certain extent. In order to explore the changing rule of the velocity head,this paper introduces the relative velocity head concept for stepped spillways by comparing the velocity head of the corresponding smooth spillway. The hydraulic model test on skimming flow has been conducted by using four different chute slopes of 26.6°,33.7°,38.7°and 51.3° at a step height of 0.5,1.0,2.0 m,focusing on the relationship of the velocity head and relative velocity head with the length of flow path,step height,unit discharge and bottom slope. An analysis of the datum shows that the relationship of velocity head of stepped spillways with those hydraulic parameter are complex while the relative velocity head of non-uniform flow is in linear with flow length,and the linear correlation coefficient between them is 0.994 8 ~ 0.998 8. The straight slope increases with the decrease in the unit discharge,and the step height and bottom slope also have an influence on the relative velocity head that increases with it,especially the bottom slope. The result shows that it is necessary to explore the relative velocity head and the unique linear relationship provides a significant basis for exploring further hydraulic characteristics of stepped spillway.

关 键 词：台阶式溢洪道 流速水头 单宽流量 台阶高度 坡度 

分 类 号：TV135.2[水利工程—水力学及河流动力学]